1. Field of the Invention
The present invention relates generally to the field of ordnance and more specifically, to the field of gun tube launched projectiles for which it may desirable or necessary to transmit data to the projectile, such data relating to characteristics of the target or characteristics of the flight path after launch, the projectile receiving such data signals while it is positioned in the gun tube just prior to firing.
2. Prior Art
Typically, the scenario involving a target and a projectile to be fired at the target involves some variable parameters that need to be taken into account in order to improve the target kill probability. Thus for example, artillery shells which utilize proximity detecting fuzes may be more optimally effective by adjusting the fuze characteristics at the last possible moment before firing. There are numerous other types of projectiles that may benefit from such capability. By way of example, there are so-called "smart" projectiles that use an infrared sensor for terminal guidance. There are circumstances under which it would be highly advantageous to transmit to the projectile a set of reference data describing the characteristics of the target just prior to firing the projectile. Transmission of such data to the projectile immediately prior to the ignition of the propulsion charge which, for example, may be used to expel the smart projectile from the gun tube, helps to assure optimum performance of the projectile. Another example is that of an artillery round that may be guided to the target by means of signals generated by the so-called "GLOBAL POSITIONING (GPS) satellite". Immediately prior to firing, a smart GPS guided round must be provided with the latest reference trajectory data, target coordinates, meteorological information and the like. Yet another example involves the use of so-called "smart multipurpose tank rounds" which can be used against a variety of targets. Depending on the target characteristics, different information must be transmitted to the projectile immediately prior to firing.
An example of prior art of substantial relevance to the present invention in that it relates to means for transmitting data directly to a projectile while it is positioned in the gun tube, relates to the manufacture of electronically programmable ordnance fuzes by Thorn EMI Electronics Ltd., of Middlesex, England. However, it is believed that this device is implemented using a conically configured induction coil which is placed over the nose or forward portion of the projectile before it is placed in the gun tube. Unfortunately, such a scheme is not conducive to the transmission of high data rates to the electronics package within the projectile immediately prior to firing. Such a system may be marginally adequate for setting simple fuzes, however, they would be entirely impractical for use in transmitting data to more sophisticated projectiles which require data to be transferred at rates many orders of magnitude greater than the prior art. By way of example, it is contemplated that the aforementioned infrared sensor terminal guidance projectile would require several thousand bits of data to be transferred within a few tens of milliseconds and the aforementioned smart GPS guided round would require in excess of 20,000 bits of data within a few tens of milliseconds. The applicant herein knows of no prior art system which possesses the capability of transferring data to a projectile positioned within a gun tube at data rates which would come even close to those required for sophisticated projectiles. However the need for such a capability increases with the sophistication of smart projectiles that are either currently being placed in the arsenal or are in the planning and design stage and are likely to be implemented in the near future.